package com.hz.tgb.image.qrcode.two.zxing.util;

import com.google.zxing.LuminanceSource;  

import java.awt.Graphics2D;  
import java.awt.geom.AffineTransform;  
import java.awt.image.BufferedImage;  

/**
 * 工具类
 * zxing下载地址：http://central.maven.org/maven2/com/google/zxing/core/
 *
 * @author hezhao
 */
public final class BufferedImageLuminanceSource extends LuminanceSource {  
  
  private final BufferedImage image;  
  private final int left;  
  private final int top;  
  
  public BufferedImageLuminanceSource(BufferedImage image) {  
    this(image, 0, 0, image.getWidth(), image.getHeight());  
  }  
  
  public BufferedImageLuminanceSource(BufferedImage image, int left, int top, int width, int height) {  
    super(width, height);  
  
    int sourceWidth = image.getWidth();  
    int sourceHeight = image.getHeight();  
    if (left + width > sourceWidth || top + height > sourceHeight) {  
      throw new IllegalArgumentException("Crop rectangle does not fit within image data.");  
    }  
  
    for (int y = top; y < top + height; y++) {  
      for (int x = left; x < left + width; x++) {  
        if ((image.getRGB(x, y) & 0xFF000000) == 0) {  
          image.setRGB(x, y, 0xFFFFFFFF); // = white  
        }  
      }  
    }  
  
    this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);  
    this.image.getGraphics().drawImage(image, 0, 0, null);  
    this.left = left;  
    this.top = top;  
  }  
  
  @Override  
  public byte[] getRow(int y, byte[] row) {  
    if (y < 0 || y >= getHeight()) {  
      throw new IllegalArgumentException("Requested row is outside the image: " + y);  
    }  
    int width = getWidth();  
    if (row == null || row.length < width) {  
      row = new byte[width];  
    }  
    image.getRaster().getDataElements(left, top + y, width, 1, row);  
    return row;  
  }  
  
  @Override  
  public byte[] getMatrix() {  
    int width = getWidth();  
    int height = getHeight();  
    int area = width * height;  
    byte[] matrix = new byte[area];  
    image.getRaster().getDataElements(left, top, width, height, matrix);  
    return matrix;  
  }  
  
  @Override  
  public boolean isCropSupported() {  
    return true;  
  }  
  
  @Override  
  public LuminanceSource crop(int left, int top, int width, int height) {  
    return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height);  
  }  
  
  @Override  
  public boolean isRotateSupported() {  
    return true;  
  }  
  
  @Override  
  public LuminanceSource rotateCounterClockwise() {  
  
    int sourceWidth = image.getWidth();  
    int sourceHeight = image.getHeight();  
  
    AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);  
  
    BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);  
  
    Graphics2D g = rotatedImage.createGraphics();  
    g.drawImage(image, transform, null);  
    g.dispose();  
  
    int width = getWidth();  
    return new BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);  
  }  
  
}